Aromatic polyketones having an aromatic ring and a carbonyl group in the main chain, disclosed in Japanese Patent Application Laid-Open (JP-A) No. S62-7730 and the like, have excellent heat resistance and mechanical characteristics. The aromatic polyketones have been used as engineering plastics. Most of polymers belonging to the aromatic polyketones are aromatic polyether ketones polymerized using nucleophilic aromatic substitution reaction, and have an ether bond in the main chain. In contrast, aromatic polyketones having no ether bond in the main chain, disclosed in Japanese Patent Application Laid-Open (JP-A) No. 2005-272728 and the like, can exhibit heat resistance and chemical resistance further superior to the heat resistance and chemical resistance of the aromatic polyether ketones.
Japanese Patent Application Laid-Open (JP-A) No. 2013-53194 reports that an aromatic polyketone with compatibility between high transparency and heat resistance can be obtained by directly polymerizing an alicyclic dicarboxylic acid and a 2,2′-dialkoxybiphenyl compound by Friedel-Crafts acylation. The aromatic polyketone has been expected to be applied to optical components.
Characteristics incapable of being obtained by inorganic materials are expected to be obtained in a case in which resin materials are applied to optical components. Examples of the characteristics include being lightweight, and being commonly softer than the inorganic materials. Examples of applications of the resin materials include materials which utilize lightweight properties and are substituted for glass for portable devices, coat materials, and flexible displays utilizing flexibility. Especially, attention has been particularly given to realization of the flexible displays in recent years.